The theoretical physicist Stephen Hawking is to receive the Royal Society's most prestigious prize for scientific achievement. The Copley medal is the oldest scientific award in the world and has been won by such luminaries as Charles Darwin, Benjamin Franklin, Albert Einstein and Captain James Cook.

The Cambridge don, most famous for his book A Brief History of Time, will be honoured in a ceremony on November 30 for his contribution to theoretical physics and theoretical cosmology.

"This is a very distinguished medal," Professor Hawking said. "It was awarded to Darwin, Einstein and [Francis] Crick. I am honoured to be in their company."

The Copley medal predates the Nobel prize by 170 years and was first awarded in 1731 - although at £5,000, it is considerably less lucrative than the roughly £750,000 on offer to Nobel laureates.

"It's a great achievement," said Roger Penrose, a physicist and mathematician at Oxford University who has worked with Prof Hawking. "It's certainly a very deserved honour." However, he is puzzled at the timing. "I wouldn't say that the work that Stephen has done more recently is of the same calibre. It's much more speculative," he said.

Prof Hawking's most significant contributions, he said, came with his work on black holes in the mid-1970s, including his discovery that they could emit radiation, now called "Hawking radiation". He said his work on combining Einstein's theory of general relativity with quantum mechanics also deserved credit.

Prof Penrose, who wrote The Emperor's New Mind, said Prof Hawking had "clearly done very good important work" but had not originated new theories as past Copley winners such as Darwin and Einstein had done. "His contribution is within the context of existing theories," he said.

The British-born astronaut Piers Sellars took the silver-gilt medal that will be awarded to Prof Hawking aboard the shuttle Discovery in July. "Stephen Hawking is a definitive hero to all of us involved in exploring the cosmos," he said.

Lord Rees, president of the Royal Society, said: "Stephen Hawking has contributed as much as anyone since Einstein to our understanding of gravity. This medal is a fitting recognition of an astonishing research career spanning more than 40 years."